Stabilized oxygen bleach-activator system

ABSTRACT

OXYGEN RELEASING BLEACHES SUCH AS PERBORATES ARE COMBINED WITH ACTIVATORS AND NONIONIC SURFACTANTS OR GLYCOLS TO PROVIDE COMPOSITIONS UNUSUALLY STABLE UPON STORAGE UNDER ADVERSE CONDITIONS OF HIGH TEMPERATURE AND HUMIDITY TO WHICH THEY ARE NORMALLY SUBJECTED.

United States Patent 3,661,789 STABILIZED OXYGEN BLEACH-ACTIVATOR SYSTEM Garland G. Corey, Milltown, and Bernard Weinsteiu, Plainfield, N.J., assignors to American Home Products Corporation, New York, N.Y.

No Drawing. Continuation-impart of application Ser. No. 843,829, July 22, 1969. This application Nov. 24, 1969, Ser. No. 879,573

Int. Cl. C01b 15/00; Clld 7/51 US. Cl. 252-186 Claims ABSTRACT OF THE DISCLOSURE Oxygen releasing bleaches such as perborates are combined with activators and nonionic surfactants or glycols to provide compositions unusually stable upon storage under adverse conditions of high temperature and humidity to which they are normally subjected.

BACKGROUND OF THE INVENTION The use of bleaching agents as aids to laundering is well known. Of the two major types of bleaches, oxygenreleasing and chlorine-releasing, the oxygen bleaches are more advantageous to use in that oxygen bleaches do not attack the fluorescent dyes commonly used as fabric brighteners or the fabrics and do not, to any appreciable extent, yellow the resin fabric finishes as chlorine bleaches are apt to do. However, one major drawback to an oxygen bleach is the high temperatures (140 F.- 160 F.) necessary to etficiently activate the bleach. The United States washing temperatures are in the range of 120 F.- 130 F., below the effective temperatures for activating an oxygen bleach. Considerable effort has been expended to find substances to activate the oxygen bleach at lower temperature.

The use of various substances as oxygen bleaches are taught. These include hydrogen peroxide and per compounds which give rise to hydrogen peroxide in aqueous solution. Suitable compounds include water soluble oxygen releasing compounds such as the alkali metal persulfates, percarbonates, perborates, perpyrophosphates and persilicates. Although not all of the preceding are true persalts in the chemical sense they are believed to provide hydrogen peroxide in aqueous solution. Among the suggested oxygen bleach activators are heavy metal salts of transition metals as cobalt, iron or copper combined with chelating agents as picolinic acid (US. Pat. No. 3,156,- 654) or stronger chelating agents at higher temperatures as methylaminodiacetic acid, aminotriacetic acid and hydroxyethylaminodiacetic acid (U.S. Pat. No. 3,211,658). Esters have been suggested as activators for oxygen re- 3,561,789 Patented May 9, 1972 leasing bleach. Exemplary are chloroacetyl phenol and chloroacetyl salicylic acid (US. Pat. No. 3,130,165), triacetyl cyanurate, N,N,N ,N -tetraacetylethylene diamine and sodium-p-acetoxy benezne sulfonate. Recently, benzoylimidazole and its derivatives with some success have been used. The problems inherent in activating oxygen bleach systems is discussed fully in, Effective Bleaching With Sodium Perborate, Dr. A. H. Gilbert, Detergent Age, June 1967, pages 18-20, July 1967, pages 30, 32, 33 and August 1967, pages 26, 27 and 67.

One major drawback which has prevented the Widespread use and acceptance of the previously described oxygen bleach-activator systems is that the activators tend to react with the oxygen bleach in the package. This results in limited efiectiveness of the bleach composition, a poor commercial product and lack of consumer acceptance. A prime requirement of a commercial bleach product is that it give standardized results, i.e., similar results from similar amounts of bleach at difierent times. The known activated perborate (oxygen) bleach compositions have failed to give such satisfactory standardized results. The premature activation in the package of the perborate bleach by the activator especially under the adversely high humidity conditions present in laundry areas results in products that continuously lose their original bleaching potential during product storage and use. This results in products which do not provide uniform results to the consumer.

OBJECT OF THE INVENTION In the light of the noted disadvantages in using oxygen (perborate) bleaches, it is an object of this invention to provide an oxygen bleach-activator system which has been stabilized against deterioration in the presence of moisture.

In general, according to this invention, the stabilization of the oxygen bleach-activator system is accomplished by using a non-ionic surfactant. The non-ionic surfactants used will preferably (although not necessarily) be liquid at ambient use temperature. The non-ionic surfactant is exemplified by the following general classes.

(1) Straight chain alkylphenoxypoly (ethyleneoxy) ethanols having the general formula:

R-Q-O omommrromomorr wherein R is an alkyl radical and n is the number of moles of ethanol oxide in the molecule (Igepals, GAF) (2) Ethoxylates of isomeric linear secondary alcohols having the general formula:

CHa-( 2)n a -(CHzCHg0);H

wherein n is the number of moles of methylene and x is the number of moles of ethylene oxide in the molecule. (Tergitols, Union Carbide.)

(3) Condensation products of ethylene oxide with a hydrophobic base formed by the condensation of propyl ene oxide with propylene glycol having the general formula:

Tao-(emulate).-oHcHzo)b-(cHzoH20),-H

wherein a and 0 represent moles of ethylene oxide and b represent moles of propylene glycol. (Pluronics, Wyandotte Chemical.)

(4) Addition products of propylene oxide to ethylene diamine followed by the addition of ethylene oxide having the general formula:

wherein x and y represent respectively the number of moles of propylene oxide and ethylene oxide in the molecule. (Tetronics, Wyandotte Chemicals.)

(5) Ethylene oxide adducts of straight chain alcohols having the general formula:

wherein x is the number of methyl groups (chiefly C to C and y is the number of moles of ethylene oxide present. (Alfonics, Conoco.)

(6) Glycols are exemplified by such as propylene glycol, triethylene glycol and trimethylene glycol.

The non-ionic surfactants or glycols are incorporated into the oxygen bleach-activator system in from about to about five times the weight of the oxygen bleachactivator used. Preferably the non-ionic surfactant is used in about equal weight amounts with the oxygen bleachactivator.

Puffed borax may also be included in the composition of this invention and is a known form of borax made by the rapid heating of hydrates of sodium tetraborate. The compound is characterized by versatility of bulk density, large surface area, rapid solubility rate, and high absorp tive potential for many substances. The puffer borax contemplated for inclusion in compositions of the invention, is further characterized by having less than 5 moles of water per mole of sodium tetraborate, a bulk density ranging from about 3 lbs/cu. ft. to about 40 lbs/cu. ft. and a particle size distribution based on the desired bulk density and the proper selection of the starting borax feed material. Found to be particularly useful are puffed boraxes having particle size distribution so that the major portion of the puffer borax is of a size within the US. sieve range of from 20 to about +200. In the more preferred forms over 90% of the particles of puffed borax are in the US. sieve range from about to 60. At the optimum compositions of the instant disclosed inventions, the bulk density of the puffed borax is about 15 lbs/cu. ft.

The oxygen bleach-activator compositions of the present invention may also include conventional additives for such compositions. These may include binders, other fillers builders, optical brighteners, perfumes, colorings, enzymes, bacteriostats, etc., all of which may be added to provide properties required in any particular instance. Additionally, the stabilized oxygen bleach-activator compositions can be incorporated into cleaning compositions containing soap and/or synthetic organic detergents and formulated for use as heavy duty household detergents, fine fabric washing detergent systems or clothes washing formulations in general.

Illustrative of the soaps which may be used in the present invention are the Well known salts of fatty acids. These may include the Na, K, Li or ammonium salts of myristic, palmitic, stearic, behenic, oleic, lauric, abietic, capric, caproic, ricinoleic, linoleic hydrogenated and dehydrogenated abietic acids, the surface active hydrolysis products of tallow, coconut oil, cottonseed oil, soybean oil, peanut oil, sesame oil, linseed oil, olive oil, corn oil, castor oil, and the like.

Illustrative of the synthetic organic detergents useful in the present invention, there may be mentioned long chain alkyl aryl sulfonates such as sodium octyl-, nonyl-, dodecyldecyl-, tri-decyl and tetradecylbenzene sulfonates, N-long chain acyl N-alkyl taurates such as sodium oleoyl methyltaurate, sodium palmitoyl methyl taurate, sodium or potassium lauroyl methyl taurate and the corresponding acyl ethyl taurates, long chain alkyl oxyethylene sulfates such as sodium or potassium laurylpolyoxyethylene sulfate, sodium laurylmonooxyethylene sulfate,

sodium octadecylpolyoxyethylene sulfate and sodium cetyl polyoxyethylene sulfate, long chain alkyl aryl oxyethylene sulfates such as ammonium, sodium or potassium nonyl-, octyl-, and tridecylphenol monoand polyoxyethylene sulfates, long chain alkyl sulfates such as sodium lauryland stearylsulfates, long chain alkyl isethionates such as sodium oleic isethionate, sodium lauric isethionate, sodium diisopropyl naphthalene sulfonate, sodium isopropyl naphthalene sulfonate, sodium isobutyland diisobutyl naphthalene sulfonate, sodium isohexylbenzene sulfonate monobutyl biphenyl sodium monosulfonate, monobutylphenylphenol sodium monosulfonate, dibutylphenylphenol sodium disulfonate, lower alkyl sulfates and sulfonates such as sodium sulfate derivative of 2-ethyl hexanol-l, sodium Z-ethyl-l-hexenyl sulfonate, sodium isooctyl sulfonate, sodium isononyl (also triisopropylyene) sulfonate, lower alkyl esters of aliphatic sulfocarboxylic acids such as sodium diamyl sulfosuccinate, sodium diisobutyl sulfosuccinate, sodium dihexyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium triamyl sulfotricarballylate, sodium triisobutyl sulfotricarballylate, and sodium tri-n-butyl sulfotricarballylate.

While the foregoing sodium salts of the above detergents may be preferred, other alkali metal and amine salts may be employed, as, for example, those with potassium ammonium, lower alkyl amines such as methylamine, ethylamine, propylamine and isopropylamine, lower alkylolamines such as mono, di-, and triethanoland isopropanolamines, cyclic amines such as cyclohexylamine, morpholine, and pyrrolidine and the like.

The above-mentioned detergents may be used alone or may be employed as mixtures. Additionally, the detergents can be used in combination with the Water-soluble soaps and water conditioners. The term water conditioner as used in the present specification and claims designates those compounds which sequester, or inactivate water hardness and aid in cleaning, and the term is fully intended to include both the inorganic and organic complexing agents, sequestering agents and chelating agents.

Referring first to the organic type of chelating and sequestering agents, the ethylene diamine tetraacetic acid type and its salts and nitrilotriacetic acid and its salts are among the most effective. While these foregoing materials are preferred, there are numerous other types of organic products offered and reference may be had to the book Chemistry of the Metal Chelating Compounds, by Martell and Ca'lvin, for many further examples. Illustrative of the inorganic water conditioners useful in the present invention are the zeolites (hydrated silicates of aluminum and either sodium or calcium or both), sodium carbonate, sodium phosphate, sodium acid phosphate, tetrasodium pyrophosphate, sodium tripolyphosphate, trisodium phosphate, sodium metaphosphate, sodium hexametaphosphate, and sodium tetraphosphate. While the sodium salts of the inorganic compounds are preferred, the other alkali metal salts such as the potassium and lithium salts may be used.

Suitable additives, e.g., binders, additional fillers, builders, optical brighteners, perfumes, colorings, bacteriostats, enzymes, etc., may be added to provide properties regarded as desirable in particular instance, as noted hereinbefore. Illustrative of some of the various additives used by those skilled in the detergent and soap art are builders (borax, sodium sulfate, sodium carbonate, etc.) corrosion inhibitors (sodium silicate), anti-redeposition agents (carboxymethyl cellulose), fabric brighteners (fluorescent or optical pigments), fillers (talc), binders (gums, starches, dextrins), coloring, foam stabilizers and suppressors, preservatives and bacteriostats and bactericides (trichlorocarbanilide, trichlorosalicylanilide, tribromosalicylanilide). Each ingredient is selected to perform a specific function. The corrosion inhibitor protects the metals used in washing machines. The anti-redeposition agent is used to aid in preventing removed soil from redeposting on the fabric being washed. The foam stabilizer or suppressor aids in tailoring the sudsing characteristics of the product. The optical brighteners aid in maintaining fabric whiteness or brightness. The enzymes aid in removing the soil from the fabric being washed.

The compositions contemplated within this invention may be prepared in any forms recognized in the art. This would include granules, powders, beads, tablets, individual premeasured units (envelopes, packets, etc.) or combinations with coatings of various materials selected to provide a difierential release rate of the ingredients forming the compositions.

The following examples are illustrative of the present invention:

EXAMPLE 1 Samples were made by mixing the activating system, BID (benzoylimidazole) with a number of fillers referred to hereinafter, and then combining the above mixture with sodium perborate monohydrate. The samples were then stored at 90 F./90% R.H. in open containers for 72 hours. The samples were removed and titrated for the amount of active oxygen present with the standard perm-anganate titration. On Table I, following column I specifies the filler tested. Columns H to IV, respectively, set out the amounts of filler, BID and sodium perborate in the compositions tested. Column V lists the measured loss under the adverse storage conditions.

TABLE 1 I II III IV V Grams Na Percent perborate active Grams Grams -H O (15.4% oxygen Filler of filler BI active 02) loss a Pufled borax b 2.00 0. 25 0. 23 22 Borax decahydrate a 2. 00 0. 25 0.23 49 Low density sodium carbonate (Flozan) 2. 00 0. 25 0.23 94 Light density sodium tripolyphosphate 2.00 0. 25 0. 23 29 Soap flakes 1 2. 00 0. 25 0. 23 55 a After 72 hours at 90 F./90% R.H. b 15 lbsJcu. it. Q 52 lbs./cu. it. d 32 lbs./cu. it.

v 33 lbs/cu. it. 1 85% tallow/15% coconut oil ratio soap having an Iodine Value (Hanus method) of 38-42.-

Table I clearly delineates the unexpected stability of oxygen bleach-activator systems containing puffed borax and those containing standard fillers including light density fillers or soaps.

EXAMPLE II A sodium perborate bleach composition was formulated into activated bleach compositions containing picolinic acid (2-pyridinecarboxylic acid) and cobalt sulfate heptahydrate (CoSO -7H O). The sodium perborate bleach composition (control) was compared to the activated bleach compositions, with and without puffed borax, after storage under adverse conditions by measuring the amount of active oxygen lost. The compositions were prepared as follows:

(a) 5 g. picolinic acid was dissolved in 100 g. ethanol to give (b) 50 g. (I) was combined with 50 g. puffed borax (6 lbs/cu. ft.) to give (11);

(c) 50 g. (II) was combined with 150 g. of a sodium perborate bleach composition to give (HI);

(d) 100 g. (III) was combined with 1 g. cobalt sulfate heptahydrate to give (IV);

(e) 100 g. sodium perborate bleach composition was combined with 0.6 g. picolinic acid and 1.0 g. cobalt sulfate heptahydrate to give (V).

6 The samples were stored in closed glass containers at F./90% RH. for 42 days. During storage the active oxygen content of the samples were measured using a standard permanganate titration.

acid and 00804.7H 0.

a From 7-42 days at 90 F./90% R.H. b Sodium perborate composition is a commercial type perborate bleaching composition containing about 4.3% available oxygen from 30% sodium perborate monohydrate, sodium tripolyphosphate, sodium silicate, sodium sulfate, non-ionic surfactant and additives such as perfumes, brighteners, etc.

The data presented in Table 2 clearly demonstrates that under the adverse test conditions the control composition showed no loss of active oxygen. The complete activated oxygen bleach activator system containing picolinic acid and cobalt sulfate showed a 49% loss under the measured adverse storage conditions; whereas, the same composition protected with puffed borax showed no loss.

EXAMPLE III A perborate activating system was prepared in the following manner: One gram of benzoylimidazole (BID) was solubilized in a non-ionic or cationic surfactant or a glycol which was liquid at ambient room temperature. Then 0.05 g. of the solubilized BID mixture was mixed with 2.00 g. of puifed borax (15 lbs/cu. ft. density). This puifed borax activator system was admixed with sodium perborate monohydrate (15.2% active oxygen) giving a BIDzNa perborate monohydrate ratio of 0.25:0.23. The sample was then stored in open containers at 90 F./7S% RH. for 72 hours, at which time active oxygen content was determined by the standard permanganate titration.

Each sample of Table 3 contains 0.25 gm. of BID and 0.23 gm. of Na PCIbOIZIlCC'I-I O.

TABLE 8 A B O D E Percent Grams Grams active suriacpuffed oxygen Sample Type of surfactant tant borax loss None 44 2. 00 23 2. 00 20 2. 00 15 2. 00 10 2. 00 ll 2. 00 22 2. 00 32 Pluronic L-61-having a molecular weight of the poloxypropylene hydrophobic base of about 1,750 and about 10% polyoxyethylene in the total molecule and an average molecular weight of about 2,000.

b Alforiic l0126having an averageiethylene oxide content of about 60% and an alkyl chain of C10 to Cu.

0 'Ietronic 701-having a molecular weight of about 3,600.

d Tergitol 15-S-9-having 0 11-015 linear alcohol and 9 moles of ethylene oxide per molecule.

B'IC 2125(50% active)(U.S. Pat. No. 2,676,986) 25% n-alkyl (60% C14, 30% C15, 5% C12, 5% C18) dimethyl benzyl ammonium chlorides, 25% n-alkyl (50% On, 30% C14, 17% C15, 3% 01a) dimethyl ethylbenzyl ammonium chlorides. 50% inert ingredients.

It is apparent from the above data that: (1) the use of puifed borax as a filler increases the active oxygen life of Na perborate. (2) the use of non-ionic surfactants tends to increase the active oxygen life of Na perborate while cationics have an opposite effect (Sample No. 8) and (3), the various non-ionics give varying results.

In a further series of experiments delineating the activity of non-ionic surfactants and glycols as stabilizers for oxygen bleach-activator systems. Equal amounts of the activator (BID) and glycol or non-ionic surfactant (0.25 g.)

were combined with a sodium perborate bleach composition. After aging under adverse storage conditions the amount of oxygen lost was ascertained using a standard permanganate titration. The results are set forth in Table 4 and clearly demonstrate that the combination containing activator and non-ionic surfactant or glycol was more stable than the combination containing the activator alone.

TABLE 4 G rams Na perborate monohydrate Grams 05-16% Percent non- G rams active active Sample Nonionie ionic BI Oz) 02 loss a 1 Pluronic L-61 0.25 0.25 0. 25 22 2 Tetronic 701 0. 25 0. 25 0. 25 20 3 Triethylene glycoL 0. 25 0. 25 0. 25 7 4 Alionie 101443. 0. 25 0. 25 0. 25 15 5 None 0.00 0. 25 0.25 38 a After 72 hr. open container at F./90% R.H.

EXAMPLE IV TABLE A B C D Sodium perborate,

mono- Triacctyl- Triethylene- Active Oz hydrate, cyanuiate, glycol, remaining, grams grams grams percent EXAMPLE V The effect of puffed borax on various sodium perborate combinations was tested. The results expressed as percent tea stain removal was measured by a Ter-gotometer after washing at 120 F. for twenty minutes. The data in Tables 6 and 7 clearly demonstrate that the effect of oxygen bleach activator is unhindered by the presence of puffed borax. The compositions are expressed as per-cent by weight.

TABLE 6.-WITH HEAVY DUTY DETERG ENT COM POSITION Sample A B C D Percent BID 5. 85 3. 30 1. 69 0. 00 Percent Na perborate monohydrate 16% active 02) 5. 15 2. 80 1. 45 2. 02 Percent puffed borax 46. 95 48. 43 48. 54 Percent detergent compos on 46. 95 48. 43 48. 54 Percent tea stain removal. 80 75 65 47 A commercially available heavy duty detergent composition com prising about 20% alkylaryl su1l'ouate,4550% sodium tripolyphosphato nd q.s. to 100% of additives.

The formulations of the present invention may be pro duced by various conventional mixing operations. These would include dry blending, spray drying and wet (slurry) blending methods. It has been found that the best stability characteristics of perborate bleaches are produced when the activator is mixed with a non-ionic (preferably liquid at ambient room temperature) and this mixture incorporated with puifed borax. If desired, small amounts (up to 5% by weight) of an alcohol such as methanol, ethanol or isopropanol may be included to act as a thinning agent in preparing the compositions of the present invention.

In general, the compositions of the present invention may comprise, by weight:

In the more preferred form, the compositions of the active ingredients of the present invention may comprise, by weight:

Filler from about 40.0% up to about 95.50%.

Oxygen bleach activator from about 1.50% up to about Oxygen releasing bleach substance from about 1.00% up to about 30.0%.

Particular compositions which utilize the principles taught by the present invention are, by weight:

(I) SPRAY DRIED BUILT OXYGEN RELEASING BLEACH [Active oxygen 2.25%]

Percent Filler (sodium silicate and sodium sulfate) 47.75 BID 2.25 Sodium perborate composition (1) 50.00

1 Composition defined in Example 11 containing 30% sodium perborate monohydrate.

(II) DRY BLENDED OXYGEN RELEASING BLEACH [Active oxygen 0.75%]

Percent Filler (sodium sulfate) 50.0 BID 6.0 Pluronic L-61 6.0 Na perborate-H O (15-16% active oxygen) 5.0 Sodium Tripolyphosphate 32.0

Adjuvantsdye, optical brightener, perfume, etc.

What is claimed is:

1. A stabilized oxygen active bleaching composition consisting essentially of an inorganic oxygen-releasing bleaching substance, an oxygen bleach activator for said oxygen-active bleaching substance and from about 0.1 to about 5 times by Weight of said activator of a glycol stabilizer selected from the class consisting of propylene glycol, triethylene glycol, and trimethylene glycol, said bleaching composition containing about 0.1% to about 25% by weight of said bleach activator and from about 0.1% to about 40% by weight of said inorganic releasing bleach substance.

2. A composition according to claim 1 wherein said glycol is triethylene glycol.

3. The composition of claim 1 wherein said stabilizing substance is present in the amount of about equal in weight to the amount of activator.

4. The composition of claim 1 wherein said oxygenreleasing bleaching substance is selected from the group 5 consisting of alkali metal persulfates, percarbonates, perborates, perpyrophosphates and persilicates.

5. The composition of claim 1 wherein said oxygenblcach activator substance is selected from the group consisting of benzoylimidazole, picolinic acid, methylaminodiacetic acid, aminotriacetic acid, hydroxymethylaminodiacetic acid, chloroacetylphenol, chloroacetylsalicyclic acid, triacetylcyanurate, N,'N,N,'N-tetraacetylethylene diamine and sodium-p-acetoxy benzene sulfonate.

References Cited UNITED STATES PATENTS 3,130,165 4/ 1964 BrocklehurSt 252-186 3,192,254 6/1965 Hayes 252-186 3,194,768 7/1965 Lindner et a1. 252-186 LEON D. ROSDOL, Primary Examiner I. GLUCK, Assistant Examiner US. Cl. X.R. 

